#include<stdio.h>

int main(){
	int a,b,c;
	scanf("%d %d %d",&a,&b,&c);
	if(a*a+b*b==c*c) printf("%d",a*b);
	else if(c*c+b*b==a*a) printf("%d",c*b);
	else if(a*a+c*c==b*b) printf("%d",a*c);
	else printf("no");
	return 0;
}
